Modern integrated circuit chips contain circuits in different regions of the integrated circuit chip running at different clock frequencies and often these circuits must send signals to each other. The clock frequencies in the different regions of the integrated circuit chip may or may not be integer ratios of each other. Further, it is often desirable to change the frequency of one or more clocks while the integrated circuits are active. Presently, methods to effect clock frequency changes require reliance on stored information of the ratio of the clock frequencies, cause glitches when the clock frequencies are changed (elongated or shorted transitional clock pulses are generated), require a system wide reset or limit the frequencies of the clock signal in some manner, all of which are not desirable in many circuit applications.
Therefore, there is a need for a method and circuit that allows dynamic clock frequency changes that does not require reliance on stored information of the ratio of the clock frequencies, cause glitches when the clock frequencies are changed, require a system wide reset or limit the frequencies of the clock signals.